let nums: number[] = [1, 2, 3, 4, 5];

let strs: string[] = ['a', 'b', 'c', 'd', 'e'];

let arr: (number | string)[] = [1, 'a', 2, 'b', 3, 'c'];

console.log(nums);
console.log(strs);
console.log(arr);